Hypoglycemic effect of hot-water extract of adzuki (Vigna angularis) in spontaneously diabetic KK-A(y) mice.
OBJECTIVE
Recently, we reported that 40% ethanol fraction of hot-water extracts of adzuki (Vigna angularis; EtEx.40) suppressed the postprandial blood glucose level and serum insulin level in normal mice and streptozotocin-induced type 1 diabetic rats. The present study examined the hypoglycemic effect of EtEx.40 on blood glucose, insulin concentrations, organ weight, serum composition, and hepatic lipid content in spontaneously diabetic KK-A(y)/Ta Jcl mice, a model for type 2 diabetes.


METHODS
To investigate the prevention of type 2 diabetes by EtEx.40 ingestion, 4-wk-old non-diabetic KK-A(y) mice were fed an AIN-76 diet containing 5000 mg of EtEx.40/kg of body weight per day (EtEx.40) or an AIN-76 diet without EtEx.40 for 8 wk. Furthermore, to investigate the improvement of type 2 diabetes, 7-wk-old diabetic KK-A(y) mice were fed EtEx.40 for 4 wk.


RESULTS
Compared with the control group, EtEx.40 supplementation had a significant effect in lowering blood glucose levels, water intake, serum insulin levels, urinary glucose, urinary microalbumin/creatinine ratio, liver triacylglycerol, and total cholesterol levels. Similar results were observed in 7-wk-old diabetic KK-A(y) mice fed EtEx.40 for 4 wk. These effects were also found after short-term administration of EtEx40. Overall, EtEx.40 improved several diabetic symptoms in KK-A(y) mice.


CONCLUSIONS
EtEx.40 obtained from hot-water adzuki extracts showed preventive and ameliorative effects on the progression of diabetes in genetically diabetic KK-A(y) mice. In the present study, we conclude that the preventive and ameliorative effects by EtEx.40 were due to the modulation of blood glucose levels and the protective effect against oxidative damage in diabetes mellitus.
Itoh
Tomohiro
T
Department of Bio-Active Substances Research, Gifu International Institute of Biotechnology, Gifu, Japan. titoh@giib.or.jp
Kobayashi
Misato
M
Horio
Fumihiko
F
Furuichi
Yukio
Y
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000235:genetics / Q000517:prevention & control*; D004195:Disease Models, Animal; D004326:Drinking / Q000187:drug effects; D006358:Hot Temperature; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000097:blood; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009929:Organ Size / Q000187:drug effects; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D019518:Postprandial Period; D011897:Random Allocation; D014867:Water
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010936:Plant Extracts; D014867:Water